Chance constrained optimal sizing of a hybrid PV/battery/hydrogen isolated microgrid: A life-cycle analysis

Abstract

Isolated microgrids offer a great potential for capturing advancements in renewable energy sources (RES) and storage technologies. Prospects for such systems include industrial, commercial, and residential areas, where grid connection is not possible or not economical. Planning isolated microgrids must be accurate, such that it preserves system security and avoids resource oversizing. This paper introduces a microgrid, composed of multiple storage components and a solar PV system, with the goal to optimally size the PV plant, battery capacity, fuel cell rating, electrolyzer rating and hydrogen tank size to match the load demand and reduce the life cycle cost of the entire system. A PV plant is used as the main energy source, while battery and hydrogen storage systems provide the maneuvering needed for covering the periods of sun absence. To accommodate PV and load uncertainties due to weather conditions, a chance constrained (CC) optimal sizing mixed integer linear programming (MILP) problem is formulated. CC optimization provides a great window for stochasticity inclusion and sizing based on criticality level of application. To prove the fidelity of the results, the system is required to achieve at least 80 % success of 100 different scenarios generated for the modeled system. The results show the capacities of the various components needed to meet the load requirements of a microgrid with a PV source, hydrogen storage system and a battery energy storage system. The total life cycle cost of the system for a period of 25 years is found to be US$1.221 m.